26 CEOCODILES. 



Although these creatures are capable of walking upon land, for which purpose they 

 are furnished with four legs, they are more fitted for the water than its shores, and are 

 swift and graceful in the one, as they are stiff, awkward, and clumsy on the other. 

 Through the water they urge their course with extraordinary speed, their long, flattened, 

 flexible tail answering the double purpose of an oar and a rudder, but on land their bodies 

 are so heavy and their legs are so weak, that they can hardly be said to walk, a term 

 which seems to imply that the body is wholly supported by the legs, but to push or drag 

 themselves along the ground, on which rests a considerable portion of their weight. 



The head of these creatures is always rather elongated, and in some species is 

 lengthened into a narrow and prolonged snout. Each jaw is furnished with a row of 

 sharply pointed and rather conical teeth. These teeth are hollow, mostly grooved on the 

 surface, and are replaced when they fall by new teeth that grow behind them, and in 

 process of time push the old ones out of their sockets. 



The nostrils are placed at the very extremity of the skull and upon a slightly raised 

 prominence, so that the animal is able to breathe by merely exposing an inch or so above 

 the water, and thus can conceal itself from almost any foe, or make an unsuspected 

 approach upon its prey. There is yet another more important use for the position of the 

 nostrils. The Crocodiles feed on fishes and various water-loving creatures, but also are in 

 the habit of lurking by the river-bank, and suddenly seizing upon any unfortunate animal 

 that may come to drink. Suppose, for example, that a calf or a dog is thus dragged into 

 the water, the reptile grasps it across the body, and sinks below the surface so as to keep 

 the head of the victim below water while itself can breathe by means of the elevated 

 nostrils. 



But as during this process the mouth is held widely open, it might be rationally 

 presumed that considerable inconvenience would be caused by the water running down 

 the throat. Such would indeed be the case, were not this difficulty provided for by a 

 simple yet very wonderful contrivance. At the back of the throat, a pair of thin 

 cartilaginous plates are so arranged, that when the animal opens its mouth the pressure oi 

 the water rushing into the mouth immediately closes one upon the other, and effectually 

 prevents the passage of a single drop, the closure being in exact proportion to the volume 

 of water. The structure indeed is very like that of the valves of the heart. The channels 

 which lead from the nostrils run very far back through the skull, and open behind the 

 throat valves, so that respiration is in no way impeded. They cannot, however, swallow 

 their prey while under water, but are obliged to bring it on shore for that purpose. The 

 tongue is small, and fastened down to the lower jaw throughout its length, so that it was 

 formerly thought that the Crocodiles were destitute of that organ. 



There is rather a curious structure in the vertebrae of the neck. These bones aro 

 furnished with short transverse processes like false ribs, which have the effect of prevent- 

 ing the animal from turning its head from side to side. On land therefore, where its feeble 

 limbs are so inadequate to the support of the long and heavy body, it can easily be 

 avoided by any one of ordinary agility. The eyes are large, and set rather far back upon 

 the head. The ears are carefully guarded from the ingress of water by a pair of tightly 

 closing valves. Below the throat are a pair of glands which secrete a substance having a 

 strong musky scent which is very disagreeable, and in old individuals taint the wholt< 

 flesh with its rank odour and render it uneatable to ordinary palates. 



The younf of these reptiles are hatched from eggs, which are strangely small in 

 proportion to the large dimensions of the adult animal, the newly hatched offspring being 

 so small as hardly to be recognised as belonging to the same species as their parents, 

 especially as there are certain differences of shape hereafter to be mentioned. 



These great reptiles are divided, or rather fall naturally, into two families, namely, tho 

 Crocodiles and the Alligators. All the members of these families can be easily distinguished 

 by the shape of their jaws and teeth, the lower canine teeth of the Crocodiles fitting into 

 a notch in the edge of the upper jaw, and those of the Alligators fitting into a pit in the. 

 upper jaw. This peculiarity causes an obvious difference in the outline of the head, the 

 muzzle of the Crocodiles being narrowed behind the nostrils, while that of the Alligators 

 forms an unbroken line to the extremity. A glance therefore at the head will suffice t 



